Social, communicational, and behavioral deficits associated with ring X Turner syndrome

We describe the cognitive and behavioral characteristics of five individual s with a ring X chromosome. All subjects had a small active (early replicat ing) ring X chromosome. The X inactive specific transcript (XIST) locus was confirmed by fluorescent in situ hybridisation (FISH) to be present in all ring X chromosomes. Mental retardation was present in four individuals. Al l patients with or without mental retardation had a characteristic profile of aggression toward self and others, episodes of screaming, attentional pr oblems, and impulsiveness. Autistic-like features were also present in all individuals and included limited communication, obsessive compulsive behavi or, and social difficulties. In some cases the obsessive behavior was extre me and incapacitating. This characteristic behavioral profile may aid the d iagnosis and future understanding of ring X, (C) 1999 Wiley-Liss, Inc.